Discovery of two simultaneous kilohertz quasi-periodic oscillations in the persistent flux of GX 349+2

We report the discovery of two simultaneous quasi-periodic oscillations in the persistent flux of GX 349+2 at frequencies 712 +/- 9 and 978 +/- 9 Hz, with rms amplitudes 1.25% +/- 0.34% and 1.34% +/- 0.32%, respectively. During our 152 ks observation with the Rossi X-ray Timing Explorer, GX 342 + 2 was in either the normal branch or the flaring branch with count rates in the nominal 2-60 keV RXTE-PCA band ranging from a low of 8000 counts s(-1) to a high of 15,000 counts s(-1). The kHz QPOs were observed only when the source was at the top of the normal branch, when the count rate was about 8200 counts s(-1) corresponding to a flux of 1.4 x 10(-8) ergs cm(-1) s(-1) in the 2-10 keV band. With this report, now kHz QPOs have been observed in all six Z sources.